Concomitant intake of abiraterone and food to increase pharmacokinetic exposure: Real-life data from a therapeutic drug monitoring program.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 3117-3117 ◽  
Author(s):  
Stefanie L. Groenland ◽  
Andre M. Bergman ◽  
Alwin Huitema ◽  
Neeltje Steeghs
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Monitoring Program ◽  
Real Life ◽  
Progression Free Survival ◽  
Abiraterone Acetate ◽  
Fixed Dose ◽  
Therapeutic Drug ◽  
Castration Resistant Prostate Cancer ◽  
Regular Treatment

3117 Background: Abiraterone acetate is registered for the treatment of metastatic castration resistant prostate cancer. Pharmacokinetic (PK) exposure has been linked to efficacy, since patients with Cmin ≥ 8.4 ng/mL have a significantly longer progression free survival compared to patients with a Cmin below this threshold (7.4 vs. 12.2 months, p = 0.044) (Carton, 2017). At the recommended fixed dose of 1000 mg QD administered in a modified fasting state, 35% of patients do not reach this efficacy threshold (Carton, 2017), providing a strong rationale for therapeutic drug monitoring (TDM). Since a clinically relevant food effect has been established, concomitant intake of abiraterone and food could offer a cost-neutral solution in case of low exposure (Chi, 2015). This study aims to evaluate whether PK-guided abiraterone dosing is feasible and results in an increased proportion of patients with concentrations above the target. Methods: Patients starting regular treatment with abiraterone were included. PK sampling occurred 4, 8 and 12 weeks after start of treatment, and every 12 weeks thereafter. Abiraterone concentrations were measured and Cmin was calculated. In case of Cmin < 8.4 ng/mL and acceptable toxicity, a PK-guided intervention was advised. As a first step, concomitant intake of abiraterone and a light meal or a snack was advised. Results: In total, 35 patients were included, of which 18 patients (51%) had at least one Cmin < 8.4 ng/mL. These patients were advised to take abiraterone concomitantly with food, after which Cmin increased significantly from 5.6 (47%) ng/mL [mean (CV%)] to 40.6 (110%) ng/mL (p = 0.006) without additional toxicities. This intervention led to adequate exposure in 15 patients (83%). Seventeen patients had all Cmin levels ≥ 8.4 ng/mL, in these patients mean Cmin was 31.5 (65%) ng/mL. Conclusions: TDM of abiraterone was applied in clinical practice and proved to be feasible. Concomitant intake with food resulted into a significant increase in Cmin and offers a cost-neutral opportunity to optimize treatment for patients with low PK exposure. Up to 100 patients will be included to evaluate the effect of PK-guided abiraterone dosing on treatment efficacy. Clinical trial information: NL6695.

Concomitant intake of abiraterone acetate and food to increase pharmacokinetic exposure: real life data from a therapeutic drug monitoring programme

2020 ◽  
Vol 130 ◽  
pp. 32-38 ◽  
Author(s):  
Stefanie L. Groenland ◽  
Merel van Nuland ◽  
Andries M. Bergman ◽  
Jeantine M. de Feijter ◽  
Vincent O. Dezentje ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Real Life ◽  
Abiraterone Acetate ◽  
Monitoring Programme ◽  
Therapeutic Drug ◽  
Life Data ◽  
Real Life Data

Real-world treatment with abiraterone acetate in patients with chemotherapy-naive metastatic castration-resistant prostate cancer (mCRPC).

2017 ◽  
Vol 35 (6_suppl) ◽  
pp. 239-239 ◽  
Author(s):  
Martin Boegemann ◽  
Martin Hatzinger ◽  
Dirko Hercher ◽  
Geoffrey Matus ◽  
Els Grieta Everaert ◽  
...  
Keyword(s):  
Real World ◽  
Treatment Duration ◽  
Radiographic Progression ◽  
Real Life ◽  
Retrospective Chart Review ◽  
Progression Free Survival ◽  
Abiraterone Acetate ◽  
Rank Test ◽  
Castration Resistant Prostate Cancer ◽  
Similar Treatment

239 Background: In the COU-AA-302 trial, abiraterone acetate plus prednisone (AAP) resulted in extension of radiographic progression-free survival (rPFS) and overall survival in chemotherapy-naïve mCRPC patients compared to prednisone alone. However, limited data on AAP treatment and outcomes is available in the real-world in this setting. The aim of this study is to describe the duration of AAP treatment in routine clinical practice in mCRPC patients prior to chemotherapy. Methods: The study was designed as a retrospective chart review of mCRPC patients identified through oncology and urology practice in Belgium, France, Germany and the UK. This first analysis reports baseline patient characteristics at AAP initiation for the first 224 patients. Treatment duration, PFS and rPFS were estimated using Kaplan-Meier curves. Potential factors associated with treatment duration were explored using the log-rank test. Results: Data from 224 mCRPC patients treated with AAP (Belgium: 67; Germany: 150; UK: 7; none from France) across 19 centres was considered in this initial analysis. At baseline, the median age was 75.5 years (interquartile range [IQR]: 69.0-82.0) and the median PSA level was 50.0 ng/mL (IQR: 21.0-121.0). Patients with visceral metastases (9.8%) and ECOG 2-3 (9.4%) were included in this study, in contrast to those included in the COU-AA-302 study. Median duration of AAP treatment was 11.6 months (95% confidence interval [CI]: 10.2-12.8), whilst median PFS and rPFS were 11.9 months (95% CI: 10.8-13.3) and 16.5 months (95% CI: 13.5-20.0), respectively. Reasons for discontinuing AAP involved PSA progression (52.2%), radiographic progression (38.9%), symptomatic progression (27.8%), non-toxic death (19.4%) and toxicity (2.2%). Treatment duration was significantly longer in mCRPC patients with either baseline ECOG status 0, lower PSA, alkaline phosphatase, aspartate aminotransferase, or lactate dehydrogenase levels (p < 0.05). Conclusions: The results of this study suggest similar treatment duration and rPFS for mCRPC patients in this real-life cohort with poorer clinical features compared to those observed in the COU-AA-302 trial population.

scholarly journals Real-life isoniazid and rifampicin plasma concentrations in children: a tool for therapeutic drug monitoring of tuberculosis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chiara Tersigni ◽  
Giulia Boiardi ◽  
Lorenzo Tofani ◽  
Elisabetta Venturini ◽  
Carlotta Montagnani ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Venous Blood ◽  
Plasma Concentrations ◽  
Age Groups ◽  
Real Life ◽  
Therapeutic Drug ◽  
Blood Samples ◽  
Drug Concentrations

Abstract Background Low plasma levels of first-line antitubercular drugs can be counted among the main causes of poor response to antitubercular therapy, and therapeutic drug monitoring has been proposed as a method to promote tailored treatments for both child and adult patients. The main aim of the study was to evaluate serum concentrations of isoniazid (INH) and rifampicin (RIF) and to investigate reasons for sub-therapeutic plasma concentrations in order to fix dosages. Methods Children with TB were prospectively enrolled from January to August 2019. Two venous blood samples were collected (the first at least 15 days after the beginning of antitubercular treatment, and the second between 1 and 8 weeks later). Plasma concentrations were determined by a validated high-performance liquid chromatography method. Results In all, 45 children were included. Seventy blood samples for INH plasma concentration were collected between 120 and 240 min after drug intake. Adjusting for dose (mg/kg/day) and time of INH administration, when considering three different age groups (≤ 2 years, 2–12 years, > 12 years), a statistically significant lower INH plasma concentration was observed in younger children compared to the older age groups in the multivariate analysis (p < 0.001 and p < 0.001). A total of 68 blood samples were evaluated for RIF concentrations. Both for INH and RIF a statistically significant lower plasma concentration was also observed in adolescents (p < 0.001). Fifteen children (15/45, 33%) presented drug concentrations under the referral therapeutic range. Conclusions Based on our findings, monitoring patients’ drug plasma concentrations in children under 2 years of age and in adolescents can make treatment more patient-tailored.

Therapeutic drug monitoring of nivolumab in clinical practice: Preliminary experience.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e14089-e14089
Author(s):  
Manuel Sureda ◽  
Ana Catalán-Latorre ◽  
Juan José Mata ◽  
Vanesa Escudero ◽  
Antonio Brugarolas
Keyword(s):  
Clinical Practice ◽  
Steady State ◽  
Therapeutic Drug Monitoring ◽  
Solid Tumors ◽  
Drug Monitoring ◽  
Cell Cancer ◽  
Plasma Concentrations ◽  
Fixed Dose ◽  
Therapeutic Drug ◽  
Multiple Tumor

e14089 Background: Fixed dose schemes, regardless of body weight, have been accepted by the regulatory agencies for the PD-1 targeting antibodies. Zaho X. and Ratain M. have elucidated that the mean steady state concentrations of nivolumab (N) at flat-doses of 240 mg Q2W or 480 mg Q4W were 57 µg/mL and 47 µg/mL, respectively. These levels are very similar to those observed at the dosage of 3 mg/kg Q2W. Considering the long half-life of N, its mechanism of action and the absence of correlation between exposure and response or toxicity at clinically tested doses, other schemes can be explored. Moreover, therapeutic drug monitoring (TDM) can contribute to individualize and optimize dosage. We determined serum N levels in patients with solid tumors. Methods: The PK profile of N was analyzed in 15 patients with solid tumors who received 3 mg/kg Q2W from May 2017 through January 2019. Eligible patients had non-small-cell lung cancer (n = 7), urothelial cancer (n = 1), gastric cancer (n = 1), breast cancer (n = 1), renal cell cancer (n = 1), colorectal cancer (n = 1), prostate cancer (n = 1), melanoma (n = 1) and sarcoma (n = 1). Free N serum concentrations were determined with a quantitative ELISA capable of detecting ≥ 0.3 µg/mL (Shikari Q-Nivo, Matriks Biotek, Ankara, Turkey). A total of 28 TDM were done after steady state (6th and 26th cycle). Results: For different reasons, 9 patients received N at 3, 4, 5, 6 or 7 week intervals once the steady state was reached. In these patients, a median reduction of 20.8% (6.7% - 43.0%) of the received doses was observed. Mean plasma concentrations of N observed after administration every 2 weeks was 73.5±32.5 µg/mL (n = 9). Once the steady state was reached, mean plasma concentrations at 3, 4, 5, 6 or 7 weeks, were 54.0±1.3 µg/mL (n = 2), 45.1±25.3 µg/mL (n = 7), 42.9±29.5 µg/mL (n = 5) and 24.4±11.7 µg/mL (n = 5), respectively. No statistically significant differences were observed in the serum levels of N between the dosing intervals of 3, 4 and 5 weeks and the standard regimen (Q2W) (p > 0.05). These data are similar to those described by Long G.V. et al. that compared N pharmacokinetic exposure for the 480 mg Q4W schedule simulated in 3817 patients across multiple tumor types with those for the 3 mg/kg Q2W and 240 mg Q2W schedules. Conclusions: The incorporation of the TDM of N in routine clinical practice could help to maintain a therapeutic drug plasma concentration with lower or less frequent doses, adding a financial benefit, without decreasing clinical efficacy. Further randomized trials to explore alternative dosing schemes of N, including personalization through TDM, are warranted

scholarly journals Fixed-dose combination and therapeutic drug monitoring in tuberculosis: friend or foe?

2016 ◽  
Vol 48 (4) ◽  
pp. 1230-1233 ◽  
Author(s):  
Marlanka A. Zuur ◽  
Onno W. Akkerman ◽  
Lina Davies Forsman ◽  
Yi Hu ◽  
Rongdong Zheng ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Fixed Dose Combination ◽  
Fixed Dose ◽  
Therapeutic Drug ◽  
Dose Combination
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